1. Field of the Invention
The present invention relates to a method for producing a layered product e.g., for use as a wound dressing or a semi-manufacture in the production of dressings, skin and wound care devices, fastening means for dressings, ostomy equipment, breast prostheses, wound drains and catheters for incontinence equipment, and for use in electrodes for application to the skin, a skin plate product producible by this method and being suitable for use as a wound dressing or a semi-manufacture in the production of dressings, skin and wound care devices, fastening means for dressings, ostomy equipment or the like, a layered product comprising a third component in the form of a discrete unit and an apparatus for carrying out the method.
2. Description of Related Art
From European Patent Application No.0 756 854 it is known to produce skin barrier wafers having a thin barrier layer of soft, pliant adhesive material with particles of one or more hydrocolloids dispersed therein, said wafers having a central zone and a relatively large outer zone surrounding that central zone. The material of the thin barrier layer in the outer zone has a generally uniform molecular orientation in radial directions which molecular orientation is caused by the barrier layer being produced by a method comprising injection and compression moulding, said method comprising the steps of:
depositing a mound of a soft, deformable skin barrier material onto a flexible first web extending along a horizontal plane and supported by a first platen;
locating a flexible second web above the first web and the mound, which second web is backed by a second platen positioned directly therein above; and
thereafter reducing the spacing between said first and second platens and compressing said mound of skin barrier material to displace a major portion of said mound of skin barrier material radially outwardly in directions extending 360xc2x0 about the original location of the deposit of said mound.
When placing a soft material as the second layer of plastic material on a sheet or web it should preferably be assured that the relaxation of the web and the forming of the plastic material is completed when the product leaves the form because complete relaxation of the web and the plastic material assures that the form of the product is maintained after the product has left the moulding cavity. One way to obtain this result is to leave the product in the mould for a longer time period. A problem with the method described in EP-A-0756854 is that increasing the time period of the product in the mould will seriously slow down the process and thus also reduce the amount of produced products. Another possibility is to increase the heat or the pressure in the compression step but increasing any of these parameters will increase the cost of the production.
European Patent Application No. 0 818 187 A1 discloses a process for making contoured dressings having a hydrocolloid-containing adhesive layer disposed between a stretchable backing layer and a planar release layer. The process comprises the step of providing a substantially continuous adhesive strip of a soft pliant adhesive material having at least one liquid absorbing hydrocolloid material dispersed therein and providing a substantially continuous supply of a backing web comprising a layer of stretchable material. The backing web is merged with the adhesive strip and the release layer to form a laminate in which said backing web has its layer of stretchable material in contact with one side of said adhesive strip and said release web is in contact with the strip""s opposite side. Then pressure is applied to the laminatexe2x80x94without stretching said layer of stretchable material in planar directionsxe2x80x94to contour the backing layer and the adhesive material of said laminate and the laminate is cut as it is being contoured to form discrete dressings of predetermined size and shape. The steps of merging the backing web with the adhesive strip, applying pressure and cutting of the laminate to form discrete dressings are all performed in a single operation in order to make the process simpler and faster compared to earlier published methods. A problem with this process might be the amount of adhesive material wasted by the cutting process if the total web is not utilised e.g., when producing dressings of curved and/or irregular contours.
EP Patent No. 573 708 discloses a method for making individual contoured wound dressings comprising:
providing a substantially continuous supply of a thin protective release covering and a substantially continuous strip of an adhesive material, where the strip of adhesive material has a predetermined thickness and malleable properties;
removably attaching the strip of adhesive material to the protective release covering while simultaneously contouring the adhesive material to a predetermined shape by merging and carrying a first laminate of the adhesive material and the protective release covering through a calibration and contouring station,
providing a substantially continuous web of an adhesive carrier material; and mergingxe2x80x94the adhesive layer to form a second laminate by applying the adhesive carrier layer to fully cover the exposed major surface of the adhesive layer while simultaneously applying pressure to the second laminate by carrying the second laminate to and through a laminating station.
Finally, the second laminate is cut into predetermined discrete sized and contoured individual wound dressings by carrying the second laminate to and through a cutting station in a predetermined registered and timed relationship.
When the adhesive material is provided as a strip it is impossible to avoid the loss of material during the cutting operation if the dressing is given a form diverting from e.g., rectangular or similar.
The German Patent Application DE 3016197 discloses a method for providing sections of elastic bands on a length of material for the production of baby pants or the like by discontinuously applying a corrugation and a liquid that solidifies into a state of elastic gum to the length of the material. Such method demands separate and accurate controlling of the application of liquid.
The object of the present invention is to provide a simple, cost efficient method for producing a layered product and a product producible by this method. The method eliminates the disadvantages known from the earlier described methods for producing layered products and furthermore the method according to the invention is sturdy, easy to control and it has a very high production rate.
The present invention relates in a first aspect to a method for production of a layered product comprising at least two layers, a first primary layer and a second mouldable layer, wherein a continuous supply of a primary layer material and a supply of mouldable material, are provided and wherein the primary layer material and the mouldable material are combined in moulding cavities.
In a second aspect, the invention relates to a layered product comprising at least two layers where a first layer is constituted by a continuous and deformable sheet, a second layer is constituted by a mouldable material which material comprises a third component in the form of individual units forming a part of the surface of the mouldable material facing away from the deformable sheet.
In a third aspect, the invention relates to an apparatus for essentially continuous production of a layered product comprising at least two layers, a first primary layer and second mouldable layer, wherein a continuous supply of a primary layer material and a supply of mouldable material are provided and where the primary layer material and the mouldable material are combined in moulding cavities.